332 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



long. 120° 35' 30" E.) ; 582 meters (318 fathoms) ; March 5, 1908; 

 fne. S., Sh. 



One specimen (Cat. No. E. 128, U.S.N.M.). 



Description. — The single specimen is of large size and in a very- 

 good state of preservation, with the arms complete. The disk, which 

 is slightly deformed, measures 21 mm. by 25 mm. in diameter; the 

 arms are from 170 mm. to 180 mm. in length. 



The disk is pentagonal with the borders more or less rounded. It 

 is covered on both surfaces with very fine and closely crowded gran- 

 ules which on the dorsal surface leave exposed only the radial shields. 

 These are very small and only measure from 1.4 mm. to 1.5 mm. in 

 length ; they are irregularly oval, and half again as long as broad. 

 The two shields of each pair are separated by a space which is almost 

 equal to the width of the arm. The granules of the dorsal surface of 

 the disk do not pass out onto the dorsal surface of the arms, and the 

 radial notches includes only the first upper arm plate. 



The ventral surface of the disk is covered with granules identical 

 with those of the dorsal surface, and some may be found which, 

 broadening somewhat, continue onto the distal border of the mouth 

 shields. These same granules are found slightly elongated all along 

 the interradial border of the genital slits, and at the base of these 

 on the free portion of the adoral plates. The genital slits are narrow. 



The mouth shields are large, triangular, with the angles and the 

 borders very rounded, almost as long as broad ; the distal border is 

 convex and it even forms a rather marked lobe which projects into 

 the interradial space, but there is not the least indication of an ac- 

 cessory shield. The adoral plates are rather small, limited to the 

 sides of the mouth shield, tapering to a point inwardly and broadly 

 separated in the median interradial line; they are outwardly very 

 much broadened, separating the mouth shield from the first side arm 

 plate. The oral plates are triangular, very low, covered with granules 

 which are a little larger than those of the rest of the ventral surface. 

 The lateral mouth papillae are seven or eight in number; the two 

 outermost are broad, rounded, almost as broad as long ; the others are 

 slender, cylindrical, and pointed. Below the group of tooth papillae 

 there are in addition two or three papillae identical with these and 

 placed on the same plane. 



The first upper arm plate is small, triangular, placed in the radial 

 notch of the disk. The following plates are very large, rectangular, 

 very much broader than long, with the sides slightly divergent. 

 Toward the tip of the arms these plates become as long as broad and 

 even a little longer than broad. They are all broadly in contact. 



The first under arm plate is small, triangular, with a rounded distal 

 apex, and broader than long ; the angles are rounded. The following 

 plates are rectangular, almost as broad as long, with a rounded distal 



